Atomistic modeling and molecular dynamics analysis of human CaV1.2 channel using external electric field and ion pulling simulations.
Biochim Biophys Acta Gen Subj
; 1863(6): 1116-1126, 2019 06.
Article
em En
| MEDLINE
| ID: mdl-30978379
ABSTRACT
BACKGROUND:
Human CaV1.2 (hCav1.2), a calcium selective voltage-gated channel, plays important roles in normal cardiac and neuronal functions. Calcium influx and gating mechanisms leading to the activation of hCaV1.2 are critical for its functionalities. Lack of an experimentally resolved structure of hCaV1.2 remains a significant impediment in molecular-level understanding of this channel. This work focuses on building atomistic hCaV1.2 model and studying calcium influx using computational approaches.METHODS:
We employed homology modeling and molecular dynamics (MD) to build the structure of hCaV1.2. Subsequently, we employed steered molecular dynamics (SMD) to understand calcium ion permeation in hCaV1.2.RESULTS:
We report a comprehensive three-dimensional model of a closed state hCaV1.2 refined under physiological membrane-bound conditions using MD simulations. Our SMD simulations on the model revealed four important barriers for ion permeation this includes three calcium binding sites formed by the EEEE- and TTTT- rings within the selectivity filter region and a large barrier rendered by the hydrophobic internal gate. Our results also revealed that the first hydration shell of calcium remained intact throughout the simulations, thus playing an important role in ion permeation in hCaV1.2.CONCLUSIONS:
Our results have provided some important mechanistic insights into the structure, dynamics and ion permeation in hCaV1.2. The significant barriers for ion permeation formed by the four phenylalanine residues at the internal gate region suggest that this site is important for channel activation.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Ativação do Canal Iônico
/
Canais de Cálcio Tipo L
/
Simulação de Dinâmica Molecular
Limite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta Gen Subj
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Canadá